Prince William met US President Joe Biden in Boston ahead of his environmental award ceremony.
Kensington Palace described the 30-minute talks between the pair as “warm, friendly and substantive”.
President Biden jokingly asked “Where’s your top?” as William neared the end of a visit to the John F Kennedy Presidential Library and Museum on a sunny but cool day.
The Prince of Wales thanked him for traveling to London for the late Queen’s funeral in September and they both shared memories of the monarch.
A palace spokesperson said Mr Biden wanted to know more about William’s Earthshot Prize and the stories of the finalists, including the Great Bubble Barrier, 2022 finalist in the Revive Our Oceans category.
William said he wanted to “amplify” the impact of his Earthshot Prize finalists to inspire a “desperate world” that there is a way forward.
He described himself as a “stubborn optimist” in an article published hours before the start of his environmental award ceremony, held in the American city of Boston.
Singer Billie Eilish will lead a stellar entertainment lineup at the ceremony, which aims to celebrate and develop environmental solutions to fix the planet.
Former England and Manchester United footballer David Beckham will present one of five prizes, with each category winner receiving £1million to develop their project.
Writing in the Huffington Post, the future king said of the finalists: “The Earthshot Prize wants to find the best of them all. We want to celebrate and support them, not only to reinforce their positive impact, but also to demonstrate to a desperate world that there is an optimistic path forward.
“The dire predictions about our natural world aren’t the only aspect of this story, and they don’t have to be our future.”
Ahead of the event taking place Friday night at Fenway’s MGM Music Hall, backstage photographs of William and Kate attending a Thursday rehearsal for the ceremony have been released.
But the couple’s three-day trip to Boston, which ends on Friday, was overshadowed by the racing line which saw William’s godmother, Lady Susan Hussey, resign as royal aide after being repeatedly questioned a prominent British-born black charity boss to find out where she’s “really coming from.”
A trailer promoting the Duke and Duchess of Sussex’s Netflix docuseries was released on Thursday, with the moment interpreted by some royal commentators as a snub to William and Kate.
William wrote about the thinking behind his award and how he was inspired by President John F Kennedy’s successful “Moonshot” ambition to put a man on the moon.
He said: “We face a challenge as seemingly insurmountable as putting a person on the moon: to reverse the damage done to our planet and put us on the path to a more sustainable future.
“Fixing our planet isn’t going to be easy, but the case for action to protect our natural world is undeniable.”
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